Interference Activity on Pipeline Systems From VSC-Based HVDC Cable Networks With Earth/Sea Return: An Insightful Review

High Voltage Direct Systems (HVDC) are in operation for many years; however, their underlying technology is rapidly advancing. Depending on technology, their operating characteristics can vary under fault and maintenance conditions. Thus, when evaluating the interference activity from such systems, expert knowledge is required with regard to the physical and electrical component aspects of transmitting HVDC electrical power. This paper provides an insightful review, by explicitly elaborating the relevance and importance of such aspects when evaluating their interference activity on collocated pipeline systems. To this end, the paper firstly elaborates on dc interference issues. However, other prevailing interference conditions rely not only on the HVDC steady-state system operation, but also on its transient conditions under dc fault conditions. This is because the transient conditions can exacerbate voltages accumulating on nearby buried pipelines -thus posing safety related concerns. In essence, the paper engages constructively with key source material and provides explicit insights and recommendations that should be considered when addressing the impact of both dc interference and short-term electromagnetic interference on pipeline systems. Exclusive emphasis is given on the operation and fault conditions of VSC-based HVDC cable networks that are using distant, earth or sea electrodes to facilitate the current return process.